On the other hand, things are falling apart fast. From rising atmospheric levels of greenhouse gases to melting icesheets and thawing permafrost, there's a very real sense that we're running out of time to tackle some of the most pressing impacts of climate change—and once certain thresholds are reached, feedback mechanisms kick in that will have a momentum all their own.

This apparent race between signs of progress and impending apocalypse is probably what keeps me up the most. And it has convinced me that even as we celebrate impressive announcements about investments in renewables, or divestment from fossil fuels, we also need to be thinking hard about how we hold back destruction—whether that's mass extinction or catastrophic sea level rise.

Two recent headlines caught my eye in this regard, both focusing on the problem of polar ice melt and sea level rise. The first, reported on over at The Guardian, was a proposal for massive engineering projects to slow down the melting of ice sheets in the Antarctic and on Greenland. Published in the latest issue of Nature, and authored by a team led by John C. Moore of the University of Lapland, the research outlines a range of measures including building sea walls to block warm water, constructing physical supports to prevent the collapse of ice sheets as they melt, and drilling into ice to pump cooled brine to the base of a glacier. While each of these projects would be cost billions of dollars to pursue, the team argues that they are both comparable with the cost of large-scale infrastructure such as airports, and significantly cheaper than the cost of doing nothing and dealing with sea level rise.

Now, I'm not qualified to argue about the feasibility of such projects. And I share the concerns of many environmentalists who see "geoengineering" as an unpredictable and potentially dangerous bet, not to mention a potential excuse not to cut emissions at the source. The researchers themselves emphasize that extensive feasibility trials, environmental impact studies, and a process for international consent would all be required before any such projects should move forward. But, they argue, the time to start discussing this is now—because once ice melts, it's hard to put it back where it once was.

In the meantime, though, maybe we should reduce our emissions? Crazy thought, I know, but the more we can reduce emissions now, the slower the warming will be, and the longer we will have to adapt and mitigate the impacts that we know are coming down the pipeline. On that front, we tend to talk mostly about carbon emissions—but Inside Climate News has a timely and helpful reminder and rundown of the various short-lived, non-carbon greenhouse gases and climate pollutants. From methane from oil exploration and agriculture, to 'black carbon' (essentially soot from shipping fuel, diesels and wood burning), and from tropospheric ozone to hydrofluorocarbons used in refrigeration, these emissions are many times more powerful by weight than carbon dioxide. But, unlike carbon dioxide, they last a matter of weeks or years—not centuries—in our atmosphere.

That means that cutting short-lived climate pollutants now could pay unusually rapid dividends, slowing down the melting of the ice sheets and buying us time to get our carbon problem in check. Here's how Inside Climate News explained the significance of short-lived climate pollutants:

The Arctic Council, an intergovernmental body that represents the eight Arctic nations and indigenous groups, has emphasized reducing black carbon and methane. Mikael Hilden, who leads the council's Expert Group on Black Carbon and Methane, said that by getting stakeholders to agree on reductions in these critical pollutants, change is possible. "It's a relatively rapid action that you can see the results quite quickly," he said."

Whether such rapid cuts would mean we won't need to construct gigantic sea walls in the Antarctic, or whether it means we'll just have longer to raise the money to do so, is not really my place to say. But I will say this: We'd better get our act together fast, because cutting emissions now is going to be a heck of a lot more cost effective than trying to deal with the impact later.